Deciding when to invest is always difficult, but imagine how difficult it would be if you owned a time machine! With so many choices, the following graphic from World Beta might come in handy. It gives a great summary of the best years to invest since 1871 — and the worst. To get to either extreme, though, you’d have to go back over 50 years: 1948 held the glory days for ten-year returns, while 1910 wasn’t so hot. Have a look: